The social infrastructures relating to means for transmitting information have advanced. This has made it possible to acquire, process, and send out many pieces and various kinds of information with the use of an information processor not only at home or office but also at other visiting places.
Under the circumstance, portable information processors such as a smartphone, a tablet, and a phablet are under active development. For example, an electronic device using a flexible display panel has been known (Patent Document 1). In addition, a multi-panel electronic device has been known (Patent Document 2).